1. Field of the Invention
The present invention relates to a disc apparatus which perform a seek operation to move an optical pickup.
2. Description of the Related Art
A disc apparatus records and reproduces data by irradiating an optical disc such as CD and DVD, on which tracks are concentrically or spirally formed to record the data, with a laser light from an optical pickup. A seek operation of the disc apparatus to move the optical pickup in a radial direction of the optical pickup enables the recording and reproduction of the data in a predetermined position of the optical disc. The seek operation which is performed before the disc apparatus records and reproduces the data is conventionally performed by moving the optical pickup to the predetermined position with counting the number of tracks. It is preferable that the seek operation is performed swiftly to shorten a waiting time for a user.
For this reason, as shown in Japanese Laid-Open Patent Publication No. 2002-352447, for example, there is a known technique that an accumulated seek distance of an optical pickup is recorded so that a seek operation is controlled in accordance with the accumulated seek distance to resolve a trouble that a time for the seek operation becomes long due to an abrasion of the disc apparatus. Moreover, as shown in Japanese Laid-Open Patent Publication No. 5-342779, there is a known technique that an optical pickup is stably moved by correcting a difference between position signals which are obtained in an outer circumference and an inner circumference of an optical disc so as to prevent the time for a seek operation from being prolonged.
However, the technique of the Patent Publication No. 2002-352447 is to resolve the problem that the time for the seek operation becomes long in accordance with the accumulated seek distance of the optical pickup, and thereby it does not shorten the time for the seek operation of the optical pickup itself. Moreover, the technique of the Patent Publication 5-342779 is to correct the difference between the position signals which are obtained in the outer circumference and the inner circumference of the optical disk, and thereby it does not enable the optical pickup to move swiftly to the predetermined position regardless of the position of the optical disc.
An object of the present invention is to provide a disc apparatus which calculates a voltage level based on the number of tracks on an optical disc which an optical pickup moves over and enables the optical pickup to move swiftly and accurately to a predetermined position by driving a motor at the voltage level.